Introduction: Assemble a HHO Mini Torch From Plumbing Parts

Picture of Assemble a HHO Mini Torch From Plumbing Parts

Using plumbing parts, consisting of some compression and some solder fittings with the addition of a  ½"  L.P. gas hosetail, its possible to make a very servicable HHO gas torch.
The temps are very low and so solder fittings will work, they also serve to keep the weight down by reducing the number of heavy brass fittings needed.
My cell produces 1 lpm so the standard mig tip will need to be made smaller and we will cover that mod later on.

Step 1: Parts and Exploded View

Picture of Parts and Exploded View
The standard 15mm plumbing fittings are...
  1. 6 inches 15mm copper tube
    • 1" section between stopend and elbow.
    • 1 ¼ " section between the coupler and the ball valve.( length is 30mm but 32mm seats well)
    • remaining approx 4" between the elbow and ball valve.
  2. 15mm copper stopend.
  3. 15mm copper 90 ° elbow.
  4. coupler FIxC 15mm x ½ "
  5. ½ " BSP hosetail which is a standard LP gas fitting.
  6. mini ball valve compression fittings on both ends.
  7. mig welder tip either 0.8mm or 0.9mm which will be modified.
  8. a brass nut M6x1.9 for the mig tip.
The mig tip has a metric thread M6x1.0 mm, so you will need to drill and tap suitable material if you dont have a M6 brass nut at hand.

Step 2: The Torch Tip

Picture of The Torch Tip

The tip is the most fiddly part of construction due to the need for swapable tips. The copper stopend is too thin to support threading for the mig tip, so a brass nut is needed that can be soldered on in the inside, in order to remove the tip. I used the earth pin from a 15A 3pin plug which I drilled and tapped for M6 thread. Another option is the brass contacts on the old carbon dry cells which would also need to be drilled and tapped.

It’s easier to first drill and tap the copper stopend and brass nut seperately and then insert a SS bolt to line the parts up when soldering, this way the ss bolt can be easily removed afterwards once all the soldering is finished.

Don’t solder with the copper mig tip in place because you won’t be able to remove it again.

I had heard mig welder tips can be made smaller by tapping a ball bearing on top. It seems odd that forcing a ball bearing down would make the hole smaller, but the copper cant spread outwards and has nowhere else to go so it constricts thereby reducing the orifice diameter which works well.

The smallest mig tip is 0.6mm which was unobtainable, I have used both the 0.9mm and the 0.8mm and managed to get the hole size down to 0.45 mm which is the size of some stainless steel leader tooth proof fishing wire I use for replacing cheese slicer wire.

Step 3: Closing Bits

Picture of Closing Bits
The body of these mini torches is usually filled with fine brass wool, which reduces the instances of flashback considerably, I have retained the insides from interferring in the ball valve with a bit of fine screen wrapped around a washer.
I used a M6 washer which I then had to grind down to fit inside the copper pipe.

Its very convenient to be able to shut off the gas at will without constant banging from flashbacks, however...

Don’t forget to switch off power to the cell once you have shut the ball valve, failure to do so will cause pressure buildup which could lead to leaks, explosions and equipment damage.


MartinA173 (author)2017-11-22

Your hho torch first you have to use Sodium Hydroxide second u should use a bubbler. You can shut off and not worry about built up pressure if u use a pressure senser in main voltage circuit, like everything else though have a bigger one i made 10 lpm

petercd (author)MartinA1732017-11-24

If you saw my other gas related 'ibles, you'd know I use a bubbler and caustic soda(lye or sodium hydroxide).

Pressure switch would be neat, but I dont want to put my trust in one considering the caustic environment.

Woodbuilder (author)2016-12-31

Can you use propane with this? If not can you rig it to make it work?

petercd (author)Woodbuilder2017-01-03

No, propane generally needs metered air at the tip. If you can find a propane jet that will fit, it should work.

bluesea8 (author)2016-07-05

I see the instructions for the tip but how about the tank for making the HHO? I know all it is is water with electric (DC) running thru it. but how do you do the plates and what is used for the tank?

petercd (author)bluesea82016-07-06

Depends on the availability of materials, I use 15mm thick perspex generally.

Make a box and clamp the lid down.

nabzim (author)2016-07-04

If you guys don't want orange flames, you need some sort of dessicant/filter to be in series with the gas hose. You need to remove the moisture from the gas, because that's the only way the sodium is being carried into the flame (it's dissolved in the microscopic water droplets that you can't see). A filter of calcium chloride (CaCl2) would be most effective, (but any common drying-agents should work), even activated charcoal may work. Just make sure it's not powdered, and that it's somewhat granulated; and if buying online, try to find products labeled "ANHYDROUS"; that is important if you want your drying agents to work like they should. Like sodium sulfate, which is a good drying agent normally, won't work if your using regular epsom salts, because epsom salt is hydrated sodium sulfate.

Also I kinda just realized you can just avoid the orange flame entirely by not putting any sodium containing electrolytes in the solution. Just use potassium ones... like, go find some potassium carbonate, and call it a day.

Poppy Ann (author)nabzim2016-07-05

on most gas torches you are able to adjust the gas mix as the orange flame is caused by to little oxygen in the mix on twin gas torches like oxyacetylene you adjust each gas separately with the valves and on single gas torches you adjust the mix normally using a rotating collar that opens and closes the air allowed into the mix with this there does not seam to be any way to adjust the air fuel mix.

Regards Poppy Ann.

nabzim (author)Poppy Ann2016-07-05

There is no air in this style of torch, the fuel and oxidizer are being created at the exact ratio thats required for combustion. For every 2 molecules of H2O being electrolyzed, there are created exactly two molecules of H2 (hydrogen gas) and one molecule of O2 (oxygen gas). A perfect ratio of combustion reactants will burn the hottest and most effecient with a blue flame, unless... your reactants are contaminated with water and sodium.

Poppy Ann (author)nabzim2016-07-05

Hi Nabzim,

I know that a blue flame is the hottest you can get which is what you do when welding with either oxyacetylene or oxypropane but even though the perfect flame is achieved with a 2 to 1 mix fuel to oxidizer the mix also depends on where you are if you are in a very humid area then you will need a little more oxygen and in a very dry area you normally need a little less.

In many years past friends and I use to build a set for home welding using a carbide lamp base which uses calcium carbide and water to produce acetylene and one of the medical oxygen cylinders both of which we could get from our local chemist the torch we made at work as they had all of the machine tools you could dream of and use in a lunch time was available, we even managed to use it to cut by heating the steel up to a orange colour then turning up the oxygen and then using the steel for a fuel whilst it was not the best way to cut it was the easiest way to mange at home as we were not allowed full size cylinders at a residential address.

forgot to say last time, a great instructable many thanks for all your work.

Regards Poppy Ann.

Dark Solar (author)nabzim2016-07-05

Wait...I thought Epsom Salt is magnesium sulfate... Now I'm confused. \: l

nabzim (author)Dark Solar2016-07-05

Although anhydrous magnesium sulfate would be a good drying agent as well... but its just too easy to buy some anhydrous calcium chloride.

nabzim (author)Dark Solar2016-07-05

Im so sorry, you are totally correct!

lukedwards (author)2016-01-25

I realize this is old but was hoping to maybe get some input. I once read that you could reduce the hole on the torch tip small enough to allow the gas to flow but actually be to small for the flame to pass through. This doesn't mean you shouldn't still use a flashback or at the very least some sort of bubbler but is yet a major additional safety feature.

I'm working with a company that has the capability of actually creating tubing in any inside and outside diameter I wish and was going to do some experimenting. It's not exactly cheap so I'm trying to accumulate all the info and advice I can in this regard. I currently have a small sample that you need a maganfying glass to even see there's a hole. They can't go much smaller than this but I actually think it's to small. I didn't write down the actual hole size for the sample they gave me.

So, can anyone here tell me the smallest size hole I can go fo mixed HHO like in this setup? If you happen to know the smallest size I can go for each of the gasses separately I'd appreciate that as well! Thanks!!

michaelmacnz (author)lukedwards2016-07-04

I read an ible a few days ago that was using a hypodermic needle for the tip. It also seemed to me that an "Ink Cartridge refilling" plastic bottle and stainless tube might be ok. What about the brass "needle" that is used for filling air into "soccer" balls ?

tnetcenter (author)lukedwards2016-07-03

The Smith Little Torch used by jewelers has several tips that have drilled rubies in them for very durable very small tip orifices - used for Propane/Oxygen set ups.

ShalorM (author)2016-07-03

Why not just use an oxy/acetylene welding tip instead of a mig tip?

AndrewW124 (author)ShalorM2016-07-03

You mean something like a brazing tip?

eddand (author)2016-07-03

perhaps use a needle valve which is superior to finely control volume accessable close to the handle. then further but still close use a ball valve for quick shut off.

ukdave56 (author)2016-04-25

If you don't use some sort of dryer the flame will be yellow, there are examples of diy dryers on the internet. The more you filter the hho the clearer it gets.

SamN2 (author)2016-01-28

could i use a propane torch valve? i might be able to machine a tip from stainless too

petercd (author)SamN22016-01-29

Screw type?

Too slow, flame will suck back to the source=boom.

PS118 (author)2013-10-10

I'm very interested in this. Particularly the fact that you can create a blowtorch that can (indirectly) burn on electricity. Of course it wouldn't make sense for heating, but as a tool.

In fact, unlike organic-combustion torches, you'd run less risk of inadvertently carbourizing your metal.

So I'm curious. How hot is this compared to standard torches? (propane/mapp/acetylene...) Also, how even is the flame?

Also, I really like your electrolysis cell. I don't know how the hose attaches, but maybe another flashback suppressor inside the cell would be a good safety feature as well.

PS118 (author)PS1182013-10-10

One more idea. Instead of using the valve to regulate the flame, could you vary the voltage to the producer cell? I'm just thinking that could eliminate some potentially exhilarating mistakes.

Notbob (author)PS1182015-03-01

I know its been about a year since you posted this, and I'm sure you've probably forgotten about it long ago...

The ideal/perfect scenario for an Oxyhydrogen flame temperature is ~2800 degC. In practise the temperature can be actually a bit lower b/c of mixing with atmospheric air (which is needed to avoid an oxidizing flame). I think some sources quote 2100+ degC on the low end of the range of flame temperatures, but I suspect this is a bit conservative.

Varying the power to the cell would work to reduce the gas output, but you wouldn't have the fine/immediate control that you get with the valve as things currently are set up in this instructable. A good solution (in my opinion) would by to incorporate both systems, using the valve for quick changes, and varying the voltage for changes in the longer time frame.

I hope this helps. Feel free to ask any more questions if you have them.

Pader (author)PS1182013-10-13

Eagle Research in America designs and manufactures commercial HHO welding units. It also publishes it's findings to enable anybody to build their units. One thing that is particularly of note in this respect is that 'blowback' normally only occurs as the gas pressure is gradually reduced, enabling the gas to follow the diminishing gas column back down the gas pipe. The ball valve in this instructable is certainly in conformity with this way of thinking as the gas goes from full pressure to off in just 90 degrees of turning instead of multiple turns of a threaded valve. A ball valve is by far, the ideal solution. By all means, use a multi-turn pipe to set up pressure before the ball valve but, the ball valve must ultimately be used to cut the gas off immediately and extinguish the flame at the torch.

Pader (author)Pader2013-10-13

I noticed an error in my reply. 'the gas pressure is gradually reduced, enabling the gas to follow the diminishing gas column' should read: 'the gas pressure is gradually reduced, enabling the FLAME to follow the diminishing gas column'.

petercd (author)PS1182013-10-10

If you hold it on anything long enough it glows red then white and turns to ash, provided of course that you have either a big enough flame or the item being melted is small enough. Directing the flame on my vice just produces water but directed on a small ball bearing quickly has it red hot and then melting. This cell produces a flame length of 50mm and the outlet hose attaches on the lid which was removed for pic and cleaning purposes.

The ball valve isnt used for flame regulation in this case, but shutting off the flame prior to switching off the cell. Voltage regulation to the cell isnt a good idea due to the fact that 2V is required for conventional electrolysis, more voltage causes heat resulting in steam and less voltage results in minimal output. The output regulation trend is to use more cells in a switchable config, ie a 48 plate cell where 12 plates are used during idle conditions but more plates can be switched in as demand increases up to the full 48 plate stack.

Kiteman (author)2013-10-10

How did you generate enough hydrogen and oxygen to feed the torch?

Why is your flame bright yellow? Stoichiometric hydrogen/oxygen* flames are normally almost invisible to the human eye, emitting mostly ultra violet light.

*So-called "HHO" is actually a stoichiometric mixture of 2 parts hydrogen and one part oxygen by volume.

kyle brinkerhoff (author)Kiteman2013-10-10

i agree. however initially i thought this whole thing was photo shopped because of the uniformity of the flame but further investigation suggested otherwise, first i went and scrutinized the image because it was not casting an appropriate amount of light for a flame that size. after that i got the metadata for the images and it checked out, then i did a quick search for hho torches and they also matched pretty closely with color, directional nature of the flame and what-not so if it is a fake, its a damn fine one at that

petercd (author)kyle brinkerhoff2013-10-11

Definitely not fake, heres another one for the files. :)
On this yellow flame issue, I've cleaned the cell replaced the caustic soda electrolyte and still get the yellow flame, even tried different focus modes on the camera to no avail. Anyhow nice work on the well researched comment, patch sent. :)

my wookie (author)petercd2013-10-17

try changing your hydrogen/oxygen levels

petercd (author)my wookie2013-10-18

I'm working with water... H2o, so Im pretty much stuck with those levels right there.

It's an electrolytic cell, voltage applied to stainless steel plates to seperate the H and O in the water, hence my misnomer HHO. Due to the fact that pure water doesnt conduct electricty in this application, I have to add a catalyst (sodium hydroxide) and the general consensus is that is causing the yellow flame color.

my wookie (author)petercd2013-10-22

have you tried using hydrogen peroxide?

petercd (author)my wookie2013-10-23

no, nor baking soda or any of the other weird kitchen concotions some folks think of.
The standard was either caustic soda( my first choice) or potassium hydroxide, new on the scene seems to be exotic mixes of those 2 with citric acid and urea, goes by the name of E-22.

my wookie (author)petercd2013-10-24

actually i meant to use that with or instead of water to change your hydrogen/ oxygen levels

Kiteman (author)my wookie2013-10-25

Hydrogen peroxide doesn't break down by electrolysis, but by decomposition to hydrogen and water. No oxygen.

Ttalos (author)Kiteman2015-01-23

It actually decomposes into water and O2.

Kiteman (author)Ttalos2015-01-24

Oops, yes, my bad.

petercd (author)my wookie2013-10-25

You're kidding right? :) Chemistry isnt like math, you dont get more hydrogen by adding peroxide, you might get something nasty, besides peroxide is 2H2O so then technically it stays the same.

my wookie (author)petercd2013-10-25

i don't mean to argue, but its actually H2O2 (underscore on the 2's) 2H2O would not have a bond between the atoms

and it actually does yield more oxygen...

kyle brinkerhoff (author)petercd2013-10-12

oh by the way, for those of you who are worried about safety this is a super simple way to take care of any concerns you have

kyle brinkerhoff (author)petercd2013-10-12

got the patch, thanks!

Kiteman (author)kyle brinkerhoff2013-10-11

Actually, I was wondering if he wasn't burning pure hydrogen/oxygen, but had something else contaminating the mix...

MikrySoft (author)Kiteman2013-10-13

Flame color looks like sodium to me and caustic soda (sodium hydroxide) electrolyte makes sense. The gas is just contaminated with a trace amounts of sodium.

Bill WW (author)Kiteman2013-10-13

Thanks Kiteman, I was reluctant to ask what the heck is HHO.

I'm with Mikry on sodium causing the yellow color. Classic test for sodium. Hydrogen flame is clear, correct?

Kiteman (author)Bill WW2013-10-14

Correct. They're quite bright in the UV spectrum, though, so I'm not sure how hazardous they are to your sight. I'd wear dark goggles, to be on the safe side.

pheenix42 (author)2015-01-12

Nice indeed! Do you happen to have a video clip of this torch in action? It's exactly what I've been looking around for!

tesla man (author)2013-12-27

I am planning on building a dry HHO cell torch that produces about 1-2 lpm. Do you think that this would be hot enough to melt table salt? (Table salt has a melting point of about 1,500 degrees F). Thanks.

petercd (author)tesla man2013-12-28

Sure will, its only if you dont have enough volume ( LPM ) and the substance is able to shed its heat faster than you can apply it, will it fail to melt. ie small flame on a big chunk of aluminium

About This Instructable




Bio: general bloke type of tinkering
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